The present invention relates generally to automated packaging machines for producing a ribbon of interconnected discrete packets, and more particularly to perforation forming modules for use in conjunction with such machines for the purpose of introducing a perforation through each packet within the ribbon.
Automated packaging machines that form a continuous ribbon of interconnected discrete packets or packages, each packet containing one or more articles such as pills or capsules, are well known. Such machines generally comprise a free standing frame; a first roll of flexible heat-sealable packaging material rotatably mounted on one end of the frame; a second coacting roll of a strip of flexible heat-sealable packaging material rotatably mounted on the other end of the frame opposite the first roll. The two strips of packaging material are guided from their respective rolls down through the frame in parallel, opposed formation. The heat-sealable portions of each strip are brought into opposed relationship.
The strips are advanced down through the frame by pull-down rolls in a predetermined sequence. Printed information such as a bar code or prescription identification is applied to one of the strips as the one strip advances through the frame. A turntable or disc is operatively mounted on the frame for feeding, in predetermined sequence, one or more pills or capsules between the two opposed strips of packaging material just as the strips are brought into contact by heat-sealing jaw members. The heat-sealing jaws are operatively disposed on the frame for heat sealing the margins on the two contacting strips of packaging material with the pill(s) entrapped therebetween. A hermetically sealed packet is thereby formed. A serration-forming knife blade is disposed on the heat sealing jaws for forming perforations on each transverse side of the packet. A cut-off blade is disposed at the bottom of the frame to severe the discrete packets from the ribbon as the ribbon advances below the pull-down rolls. A drive motor assembly is provided for activating the pull-down rolls, the turntable, the heat sealing jaws, and the cut-off blade.
A machine of the aforementioned type is taught and disclosed by U.S. Pat. No. 4,493,178, issued Jan. 15, 1985, and sold commercially by Euclid Spiral Paper Tube Corp., of Apple Creek, Ohio 44606 under the trade names CADET and CADET TWIN. The machines represent reliable means for automatically packaging pills or capsules into discrete packets for distribution to end patients and has met with enthusiastic acceptance in the medical treatment and pharmaceutical industries.
A recent development in the medical industry has been the creation of automated inventory systems that organize, select, and dispense packets, combinations of packets, to end patients. In such automated inventory systems, packets of medication, such as those created by the machine set forth in U.S. Pat. No. 4,493,178, are suspended from pegs along an inventory wall in an organized fashion. A computer controlled robotic machine is used to traverse the inventory wall and select appropriate packets by scanning the bar codes on each packet. The selected packets are mechanically removed from their respective peg and transported to a collection station, combined with other packets as necessary, and ultimately dispensed to end patients.
In order to facilitate suspension of the packets from pegs along such an inventory wall, it is required that each packet formed with perforation. The perforation must be appropriately sized and cleanly formed through the packet so as to allow the robotic picking machine to predictably attach and remove each packet from its associate wall peg. Moreover, the perforation through each packet must be formed in an efficient, preferably automated, manner that does not unduly add cost to the end package. Finally, the introduction of a perforation into each packet must be done in a manner that does not physically deform of the packet to an extent that would make the bar code or information printed on the packet illegible or compromise the integrity of the packet.
It is, therefore, an objective of the invention to provide a perforation forming module that efficiently and reliably introduces a perforation into a flexible manufactured packets.
A further objective is to provide a perforation forming module capable of automated use in conjunction with commercially available packaging machines.
Yet a further objective is to provide a perforation forming module for automated packet manufacturing machines capable of introducing a clean perforation into packets manufactured by such machines without detrimentally affecting the speed or efficiency of the manufacturing operation.
Another objective is to provide a perforation forming module for automated packet forming machines having high structural and functional reliability and requiring a relatively low level of maintenance.
Still a further objective is to provide a perforation forming module for automated flexible packet forming machines that efficiently, reliably, and automatically introduces a perforation into each packet manufactured by such machines without physically deforming or compromising the integrity of each flexible packet.
A further objective is to provide an efficient and reliable perforation forming module that is mechanically and functionally compatible with commercially available packet forming machines.
These, and other objectives that will be apparent to those skilled in the art, are achieved by an embodiment disclosed herein. The invention comprises a perforation module for packaging machines of the type that convert strip material into a ribbon of interconnected flexible packets. Commercially available packet forming machines comprise a strip feeder for feeding dual parallel strips of material along a feed path to a packet forming station located along the feed path above the strip feeder. Opposed heat sealing jaws within the packet forming station, on opposite sides of the feed path, meet intermittently along the feed path to form sealed flexible packets interconnected as a continuous ribbon.
The perforation module comprises first and second punch die assemblies disposed along the strip feed path between the strip feeder and the heat sealing jaws. The punch die assemblies are aligned with each other on opposite sides of the strip feed path and synchronously move in reciprocal fashion between retracted and closed positions to introduce a perforation into each packet leaving the packet forming station. The punch die assemblies are synchronized with the heat sealing jaws to meet along the strip feed path as the jaws are clamped against the strip material and the strip material is held in tension between the heat sealing jaws and the strip feeder.
The punch die assemblies comprise parallel guide rods that direct the die assemblies between the retracted and closed positions. One punch die assembly, in the preferred embodiment, is mounted to a common support block with one heat sealing jaw and moves unitarily therewith between the retracted and closed positions.
A further aspect of the invention is a method of performing a perforation operation in a packaging machine of the aforementioned commercial type. The method comprises the steps of interposing first and second punch die assemblies along the strip feed path between the strip feeder and the heat sealing jaws; aligning the punch die assemblies with each other on opposite sides of the strip feed path; moving the punch die assemblies into the feed path to perform a perforation forming operation; and synchronizing the movement of the punch die assemblies so that the perforation forming operation occurs while the sealing jaws are in clamping engagement with the strip material and the strip material is held in tension between the heat sealing jaws and the strip feeder.